1. Field of the Invention
The present invention relates to a water-cooled vertical engine having a crankshaft disposed substantially vertically, and to an outboard motor equipped with the water-cooled vertical engine.
2. Description of the Related Art
As a vertical engine for an outboard motor, a water-cooled engine is generally used. In an outboard motor water-cooled engine disclosed in Japanese Patent Application Laid-open No. 10-212948, a thermostat for controlling the flow of cooling water within a water jacket in accordance with the temperature of the cooling water is disposed in an upper part of an engine block, and a timing belt, via which a camshaft is driven by a crankshaft, is disposed in the upper part of the engine block.
The thermostat thus disposed in the upper part of the engine block can detect the temperature of cooling water that has been supplied from the lower end of the water jacket and has carried out heat exchange, thus enabling the flow of cooling water to be controlled appropriately. Furthermore, since the timing belt is disposed in the upper part of the engine block, assembly and maintenance thereof can be made easy.
However, in the above-mentioned arrangement, since the thermostat is disposed within a cover for covering an upper part of the timing belt, there is the problem that it is necessary to remove the cover for maintenance of the thermostat, and the workability is therefore poor. In order to facilitate the maintenance of the thermostat, providing the thermostat on an upper face of the cover for covering the upper part of the timing belt can be considered, but this requires a cooling water pipe for providing a connection between the thermostat and a water jacket provided in the engine block, resulting in increases in the number of components and the number of assembly steps.
Moreover, when a thermostat for controlling the flow of cooling water in a cylinder block cooling water jacket and a second thermostat for controlling the flow of cooling water in a cylinder head cooling water jacket are provided separately, it is necessary to arrange the two thermostats compactly in a confined space of an upper part of the engine.